The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs. Each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs. For example, a semiconductor structure typically includes a metallization layer disposed over a substrate, where the metallization layer that provides interconnections to devices (such as transistors, capacitors, resistors, and/or other active and passive devices) formed on the substrate. An inter-metal dielectric (IMD) layer disposed over the typically includes interconnects (such as vertical interconnects) connected to conducive lines of the metallization layer.
When forming the interconnects in the IMD layer, various photolithographic and etching processes are performed to form an opening (which can include one or more holes) in the IMD layer, which is subsequently filled with a conductive material. Typically, a number of holes formed in the IMD layer equals a number of photolithographic and etching operations performed on the IMD layer. For example, a two patterning, two etching (2P2E) process is typically performed to form an opening in the IMD layer that includes two holes, a three patterning, three etching (3P3E) process is typically performed to form an opening in the IMD layer that includes three holes, a four patterning, four etching (4P4E) process is typically performed to form an opening in the IMD layer that includes four holes, and so on. Such processing is not only very inefficient, but also very costly. A need therefore exists for a process that can form openings (for example, having more than one hole) in semiconductor processing layers, such as the IMD layer, in a relatively efficient and cost effective manner.